1.1 Earth's Interior

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Vocabulary

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Geologists: scientist who study the forces that make and shape the Earth
Rock: the material that forms most of the Earth's surface
Geology: the study of Earth
Constructive forces: forces that shape the surface by building up mountains and landmasses
Destructive forces: forces that slowly wear away mountains and, eventually, every other feature on the surface
Continents: the seven great landmasses on Earth
Seismic waves: are produced when earthquakes occur
Pressure: the pushing on a surface or area
Crust: a layer of rock that forms Earth's outer skin
- Basalt: a dark, dense rock with a fine texture (usually found in oceanic crust)
- Granite: a rock that has larger crystals than basalt (usually found in continental crust)
Mantle: a layer of hot rock between the crust and above the core
Lithosphere: a rigid layer that contains the crust and the uppermost part of the mantle
Asthenosphere: a soft layer under the lithosphere ( the material can flow easily in this layer)
Outer core: a layer of molten metal that surrounds the inner core
Inner core: a dense ball of soled metal

Outline

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The Science of Geology

• studying surface changes
  • the surface is constantly changing
• finding indirect evidence
  • we can't get to the middle of the Earth
  • instead of digging a hole we use seismic waves
    • Geologists record the seismic waves when an earthquake happens( they study the paths the waves take)

A Journey to the Center of the Earth

• temperature changes
  • rocks are cool near the top
  • about 20 meters down, the rocks are getting warmer
  • the temperatures rises 1 Celsius ever 40 meters
    • that's pretty hot for the temperature down there
• pressure also changes
  • as you go deeper the pressure increases

The Crust

• There are two kinds of crusts
  • Oceanic Crust
    • the oceanic crust contains mostly basalt
      • darkly colored
  • Continental Crust
    • the continental crust contains mostly granite
      • lightly colored

The Mantle

• the lithosphere contains part of the mantle
  • the lithosphere is about 100 kilometers thick
• the asthenosphere is what the lithosphere floats on
  • the asthenosphere is the lowest part of the mantle

The Core

• there are two parts that are called the "core"
  • The Outer Core
    • the outer core is a layer of molten metal
  • The Inner Core
    • extreme pressure squeezes the atoms of the iron so much they can't spread
    • the core makes about one third of Earth's mass but only 15 percent of its volume

Earth's Magnetic Field

• the magnetic fields are created by the core
  • the inner core moves, this movement creates this field
    • the magnetic field causes the Earth to act like a big magnet bar
  • without the magnetic field, we would get burned from the sun's harmful rays (like the ultra violet rays)

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